The use of a releasable spring-biased latch of the type found on many containers is not common in safe design as most safes are intended for the highest security. They are generally locked and only temporarily unlocked when necessary to access their contents. Thus, there has generally been no need for the expedient of a releasable latch where safes are concerned. However, the new small portable fireproof safes produced by the assignee of this invention have been found to have advantages and requirements different from those typically associated with safes. We believe it would be helpful to provide a releasable latch as well as a lock for use with such safes. However, cost and efficiency weigh against the use of a separate lock and latch for the same safe. Some type of cooperative lock and latch assembly meeting the requirements of safe design is required.
We have found no examples of such assemblies in safe design. However, there are latch and lock combinations in use in other applications. For example, U.S. Pat. No. 3,025,692 issued to Cheney in 1962 deals with “Key-Locked Fastenings for Travel Bags, Boxes and the Like.” Likewise, U.S. Pat. No. 3,106,082 issued to Payor et al. in 1963 for a “Lock for Baggage, Etc.” teaches a hinged exterior latch member on the lid of a case. Finally, U.S. Pat. No. 3,998,077 issued to Bako in 1976 describes a “Draw Bolt” for use with a case. Cheney, Payor, and Bako disclose case latch arrangements in which an internal catch or catches engage part of a lid-mounted, hinged exterior latch member. To release the latch, the user uses exterior buttons that slide the catch(es) out of engagement with the latch. A lock prevents this operation from taking place. However, exterior latch members are not suitable for use with safes, which require a higher level of security. Moreover, latching in these inventions is not automatically effected by closure. This, once again, adversely affects security and is more inconvenient to the user. Finally, a latch member that swings in a plane perpendicular to the front of the case is not in keeping with the compactness required for a latch of the type we contemplate.
A more sophisticated device for use with a case is disclosed in U.S. Pat. No. 4,813,253 issued to Dumas in 1989 for a “Safety Locking Device for an Article, in Particular Luggage, and an Installation Including Said Device.” Dumas teaches a closing device including a rigid planar latch attached to the lid of a case with a pivoting spring-biased planar catch or keeper located in the base. These two elements are set in the same plane and have cam surfaces that enable them to snap together. A button can move the catch element out of the plane of the latch, allowing these parts to disengage, while a lock interposes an element that keeps the catch from sliding out of the plane of the latch and disengaging. The Dumas apparatus avoids most of the problems associated with the prior art devices previously discussed and comes closer to meeting the needs for a portable fireproof safe; however, there remains a need for lockable latches suitable for use in this application.